JP2023053683A - Screw for optical axis adjustment and vehicle lamp including the same - Google Patents

Abstract

To provide an optical axis adjustment screw, that achieves weight reduction while maintaining a necessary mechanical strength, and a vehicular lamp including the same.SOLUTION: There is provided a resin optical axis adjustment screw 100 for adjusting a light emission direction of a vehicle lamp. The optical axis adjustment screw 100 includes a skin layer 110 formed on a surface of the optical axis adjustment screw 100, and a foam layer 120 formed inside the skin layer 110 and containing a plurality of cells 121. An average diameter of the cells 121 in the foam layer 120 is 10 to 100 μm.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to an optical axis adjusting screw and a vehicle lamp including the same.

2. Description of the Related Art A vehicle lamp such as a headlight is provided with an optical axis adjusting screw as a part of an aiming mechanism for adjusting an optical axis direction that serves as a reference for a light irradiation direction. For example, U.S. Pat. No. 6,200,000 discloses an optical axis adjustment screw having a hollow portion extending over at least a portion of an intermediate portion between first and second ends. Further, Patent Document 1 discloses that the optical axis adjustment screw is made of resin and formed by injection molding.

In general, resin parts are manufactured by various methods according to their shapes and materials. For example, Patent Document 2 discloses manufacturing a resin product having internal foams by introducing a polymer material mixed with a supercritical fluid into a mold and then solidifying the polymer material in the mold. It is

JP 2019-130712 A JP 2007-15398 A

In recent years, vehicular lamps have become larger and heavier as they have become more sophisticated, such as by being equipped with ADB (Adaptive Driving Beam) technology. In view of this background, some parts that constitute the vehicle lamp are required to be lightweight while maintaining necessary mechanical strength. The optical axis adjustment screw described in Patent Document 1 has a hollow portion in a part of the screw to reduce weight while maintaining necessary mechanical strength. It is also important to consider other methods in today's world.

Patent Literature 2 describes that the inside of the resin product is foamed to reduce the weight of the resin product, but does not describe application to an optical axis adjusting screw. Naturally, there is no disclosure of how to achieve both the necessary mechanical strength and weight reduction in the optical axis adjustment screw.

SUMMARY OF THE INVENTION An object of the present disclosure is to provide an optical axis adjusting screw that is lightweight while maintaining necessary mechanical strength, and a vehicle lamp including the same.

An optical axis adjusting screw according to an aspect of the present disclosure includes
A resin-made optical axis adjusting screw for adjusting the light emitting direction of a vehicle lamp,
a skin layer formed on the surface of the optical axis adjustment screw;
a foam layer formed inside the skin layer and containing a plurality of cells,
The average diameter of the cells in the foam layer is 10 to 100 μm.

A vehicle lamp according to an aspect of the present disclosure includes the optical axis adjusting screw.

Advantageous Effects of Invention According to the present disclosure, it is possible to provide an optical axis adjusting screw and a vehicle lamp including the same that are lightweight while maintaining necessary mechanical strength.

1 is a schematic cross-sectional view showing a vehicle lamp according to an embodiment of the present disclosure; FIG. FIG. 3 is a schematic diagram showing an optical axis adjusting screw according to an embodiment of the present disclosure; FIG. 3 is a schematic diagram showing the internal structure of an optical axis adjusting screw according to an embodiment of the present disclosure;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described based on embodiments with reference to the drawings. The same or equivalent constituent elements, members, and processes shown in each drawing are denoted by the same reference numerals, and duplication of description will be omitted as appropriate. Also, the dimensions of each member shown in the drawings may differ from the actual dimensions of each member for convenience of explanation. Also, the "front", "rear", "up", and "down" directions shown in the drawings are relative directions set for convenience of explanation. As used herein, the term "front-back direction" refers to a direction including forward and backward directions, and the term "vertical direction" refers to a direction including upward and downward directions.

(vehicle lamp)
First, a vehicle lamp according to an embodiment of the present disclosure will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view (longitudinal cross-sectional view) showing a vehicle lamp 1 according to this embodiment. A vehicle lamp 1 shown in FIG. 1 is, for example, a headlamp of a vehicle, and is arranged on the left and right in front of the vehicle. The left and right vehicular lamps 1 have substantially the same configuration except that they have a symmetrical structure. Note that each direction shown in FIG. 1 can be a direction based on the vehicle when the vehicle lamp 1 is attached to the vehicle.

A vehicle lamp 1 includes a lamp body 2 having an opening on the vehicle front side, and a translucent cover 3 covering the opening of the lamp body 2 . A lighting unit 4 is accommodated in a lamp chamber 7 formed by the lamp body 2 and the translucent cover 3 .

The illumination unit 4 is configured to form a light distribution pattern by emitting light toward the outside (forward) of the vehicle. Although not shown, the illumination unit 4 has a light source that emits light and an optical system. The light source may include, for example, light emitting elements such as LEDs (Light Emitting Diodes), LDs (Laser Diodes), or organic ELs (Electro Luminescence). The optical system includes a reflector configured to reflect the light emitted from the light source toward the front of the lighting unit 4 and a component configured to refract the light directly emitted from the light source or the light reflected by the reflector. and/or lenses.

The lighting unit 4 is attached to the vehicle lamp 1 via a first bracket portion 5 a extending upward from the lighting unit 4 and a second bracket portion 5 b extending downward from the lighting unit 4 . The first bracket portion 5a has a screw hole at a predetermined position. The lamp body 2 also has a screw support portion 21 at a position overlapping the screw hole in the front-rear direction. The screw support portion 21 is, for example, a tubular member extending in the front-rear direction, and is provided so as to communicate the inside and outside of the lamp body 2 .

An optical axis adjusting screw 100 is inserted through the screw support portion 21 from the outside of the lamp body 2 . The optical axis adjustment screw 100 is rotatably supported by the screw support portion 21 . Further, the optical axis adjusting screw 100 is screwed into the screw hole of the first bracket portion 5a. The structure of the optical axis adjustment screw 100 will be detailed in a later paragraph.

A pivot portion 6 is provided at a predetermined position of the second bracket portion 5b. The pivot portion 6 is a member projecting rearward from the second bracket portion 5b. A ball for a ball joint is provided at the rear end of the pivot portion 6 . The lamp body 2 also has a joint receiving portion 23 at a position overlapping the pivot portion 6 in the front-rear direction. The joint receiving portion 23 is a member that protrudes forward from the lamp body 2 and has a ball accommodating portion at its tip. The ball of the pivot portion 6 is rotatably connected to the ball receiving portion of the joint receiving portion 23 .

The first bracket portion 5a, the second bracket portion 5b, the optical axis adjustment screw 100, the pivot portion 6, and the joint receiving portion 23 are part of an aiming mechanism for adjusting the optical axis direction of the illumination unit 4. By rotating the optical axis adjusting screw 100, the lighting unit 4 can be tilted with the ball of the pivot portion 6 as a fulcrum, and the optical axis of the lighting unit 4 can be adjusted in the vertical direction. Although illustration is omitted, the lighting unit 4 is connected to two optical axis adjusting screws 100 arranged in the horizontal direction via a bracket portion. Therefore, it is possible to adjust the optical axis of the lighting unit 4 also in the horizontal direction.

The vehicle lamp 1 only needs to include at least the optical axis adjusting screw 100, and other configurations are not limited to the above examples. As for the configuration other than the optical axis adjustment screw 100, a conventionally known configuration can be adopted.

(Screw for optical axis adjustment)
The optical axis adjusting screw 100 is a member for adjusting the light emitting direction of the vehicle lamp 1 , that is, the optical axis of the lighting unit 4 . Although the optical axis adjustment screw 100 is made of resin, it may partially contain metal. The structure of the optical axis adjusting screw 100 will be described in detail below with reference to FIGS. 2 and 3. FIG.

FIG. 2 is a schematic diagram (side view) showing the optical axis adjusting screw 100 according to an embodiment of the present disclosure. As shown in FIG. 2, the optical axis adjusting screw 100 includes a screw portion 103, a connecting portion 104, a support shaft portion 105, an engaging portion 106, and It has

The screw portion 103 is formed on the front end portion 101 side. The threaded portion 103 is provided with a threaded groove that is screwed into the threaded hole of the first bracket portion 5a. The support shaft portion 105 is formed on the rear end portion 102 side. The support shaft portion 105 is supported by the screw support portion 21 . The support shaft portion 105 may be provided with a sealing member (such as an O-ring) for preventing moisture from entering the lamp chamber 7 . The connecting portion 104 is formed between the screw portion 103 and the support shaft portion 105 .

The engaging portion 106 protrudes from the connecting portion 104 so as to extend from the screw portion 103 side to the support shaft portion 105 side. Further, the engaging portion 106 is formed so as to be able to contact the front end portion of the screw support portion 21 in a state where the support shaft portion 105 is supported by the screw support portion 21 .

The engaging portion 106 can be elastically deformed in directions approaching and separating from the connecting portion 104 . When the optical axis adjusting screw 100 is inserted through the screw support portion 21 , the engaging portion 106 is pressed against the inner wall of the screw support portion 21 and elastically deformed in a direction toward the connecting portion 104 . Then, when the entire engaging portion 106 has passed through the screw support portion 21 , the engaging portion 106 is elastically restored in a direction away from the connecting portion 104 . As a result, the rear end of the engaging portion 106 contacts the front end of the screw support portion 21 . Such a mechanism prevents the optical axis adjusting screw 100 from coming off from the lamp body 2 . Although the number of engaging portions 106 is not particularly limited, from the viewpoint of reducing the load applied to each engaging portion 106, a plurality of engaging portions 106 are provided so as to form a pair at positions facing each other across the connecting portion 104. is preferred.

FIG. 3 is a schematic diagram showing the internal structure of the optical axis adjusting screw 100 according to one embodiment of the present disclosure. A region X shown in FIG. 3 shows the internal structure of the support shaft portion 105 . As shown in region X, support shaft 105 includes skin layer 110 and foam layer 120 . Other portions such as the screw portion 103 and the connecting portion 104 of the optical axis adjusting screw 100 also have a skin layer 110 formed on the surface thereof and a foam layer 120 formed inside the skin layer 110. sell.

The optical axis adjusting screw 100 including the skin layer 110 and the foam layer 120 can be manufactured, for example, by micro-injection foam molding using a supercritical fluid. Specifically, a single-layer melt obtained by uniformly mixing and dispersing a supercritical fluid (such as nitrogen or carbon dioxide) in a plasticized resin is placed in a mold cavity while controlling the pressure and temperature. It can be manufactured by injecting into The resin is not particularly limited, but thermoplastic resins such as polycarbonate resin, polypropylene resin, acrylic resin, ASA (Acrylate Styrene Acrylonitrile) resin, and ABS (Acrylonitrile Butadiene Styrene) resin can be used. The method for manufacturing the optical axis adjusting screw 100 is not limited to micro-injection foam molding, and other conventionally known manufacturing methods may be used.

Skin layer 110 is formed on the surface of support shaft portion 110 . The skin layer 110 is a layer substantially free of air bubbles. Note that “substantially free of air bubbles” means, for example, that the skin layer 110 does not contain air bubbles of a size and quantity that significantly affect the weight and mechanical strength of the skin layer 110 . Although the thickness of the skin layer 110 is not particularly limited, it is preferably 10 μm or more and 1000 μm or less, for example.

The foam layer 120 is a layer formed inside the skin layer 110 . Foam layer 120 includes a plurality of cells 121 . By including a plurality of cells 121 in the foam layer 120, the lightness of the optical axis adjusting screw 100 is improved.

The average diameter of the cells 121 in the foam layer 120 is 10 μm or more and 100 μm or less from the viewpoint of achieving both necessary mechanical strength and lightness. From the same point of view, the average diameter of the air bubbles 121 is preferably, for example, 20 μm or more and 90 μm or less, and more preferably 30 μm or more and 80 μm or less. In addition, the "average diameter of bubbles" refers to the average value of the diameters of arbitrary 20 bubbles when the cross section is observed using a scanning electron microscope (SEM).

In addition, from the viewpoint of suppressing a decrease in mechanical strength, the maximum diameter of the cells 121 in the foam layer 120 is, for example, preferably 100 μm or less, more preferably 60 μm or less, and 40 μm or less. More preferred.

The average diameter and maximum diameter of the bubbles 121 can be controlled by adjusting the injection speed, for example. Generally, when the injection speed is fast, the average diameter and maximum diameter of the bubbles 121 are small, and when the injection speed is slow, the average diameter and maximum diameter of the bubbles 121 are large. Note that the average diameter and maximum diameter of the bubbles 121 can also be controlled by adjusting the temperature and pressure inside the mold.

In addition, the foaming rate of the foam layer 120 is, for example, preferably 1.0% or more, more preferably 1.5% or more, and even more preferably 2.0% or more, from the viewpoint of reducing weight and suppressing the occurrence of sink marks. . From the viewpoint of ensuring mechanical strength, the foaming rate of the foam layer 120 is preferably 10.0% or less, more preferably 5.0% or less, and even more preferably 4.0% or less. The "foaming ratio" (%) is a value that indicates the weight loss due to foaming. Calculated.

A region Y shown in FIG. 3 shows the internal structure of the engaging portion 106 and part of the internal structure of the connecting portion 104 . As shown in the region Y, the vicinity of the end portion of the engaging portion 106 on the threaded portion 103 side, that is, the vicinity of the base of the engaging portion 106 is formed only of the skin layer 110 and does not include the foam layer 120 . The vicinity of the base of the engaging portion 106 is a portion that is easily damaged because the load is concentrated when preventing the optical axis adjusting screw 100 from slipping out of the lamp body 2 . The optical axis adjusting screw 100 according to the present embodiment has the skin layer 110 only in the vicinity of the root of the engaging portion 106, so that the mechanical strength is increased compared to the case where the foam layer 120 is included. It is difficult to cause damage near the root.

In order to form the vicinity of the base of the engaging portion 106 only with the skin layer 110, for example, the injection conditions such as the injection speed, temperature or pressure, and the thickness of the vicinity of the base of the engaging portion 106 may be appropriately set. The thickness d near the base of the engaging portion 106 is, for example, preferably 0.8 mm or more and 2.4 mm or less, more preferably 1.0 mm or more and 2.0 mm or less, and even more preferably 1.1 mm or more and 1.8 mm or less.

The mold used for injection molding is provided with gas vent holes at a plurality of locations. It is preferable to provide a vent hole that is larger than the other portions. With such a configuration, even if the thickness d near the base is small, it becomes easy to fill the resin up to the tip of the mold.

The internal structure of the connecting portion 104 is a structure having a skin layer 110 on the surface and a foam layer 120 inside the skin layer 110 , similar to the support shaft portion 105 . Since the connection portion 104 is thinner than the support shaft portion 105 and is easily loaded, from the viewpoint of ensuring mechanical strength, the average diameter and the maximum diameter of the cells 121 in the foam layer 120 are set to be smaller than that of the support shaft portion 105. Smaller is preferred. In general, the later the mold is filled, the larger the bubble size tends to be. Therefore, for example, by filling the connection portion 104 after the support shaft portion 105 at the time of injection, the average diameter and the maximum diameter of the cells 121 in the foam layer 120 of the connection portion 104 can be reduced to those of the support shaft portion 105. can be smaller than

It should be noted that the present invention is not limited to the above-described embodiments, and can be modified, improved, etc. as appropriate. In addition, the material, shape, size, numerical value, form, number, location, etc. of each component in the above-described embodiment are arbitrary and not limited as long as the present invention can be achieved.

1: Vehicle lamp 2: Lamp body 3: Translucent cover 4: Lighting unit 5a: First bracket part 5b: Second bracket part 6: Pivot part 7: Lamp chamber 21: Screw support part 23: Joint receiving part 100: Optical axis adjustment screw 101: Front end 102: Rear end 103: Threaded portion 104: Connecting portion 105: Support shaft portion 106: Engagement portion 110: Skin layer 120: Foam layer 121: Bubbles d: Thickness

Claims (4)

A resin-made optical axis adjusting screw for adjusting the light emitting direction of a vehicle lamp,
a skin layer formed on the surface of the optical axis adjustment screw;
a foam layer formed inside the skin layer and containing a plurality of cells,
The average diameter of the cells in the foam layer is 10 to 100 μm,
Optical axis adjustment screw. a threaded portion formed on the front end side;
a support shaft portion formed on the rear end side and supported by the screw support portion of the vehicle lamp;
a connecting portion formed between the threaded portion and the support shaft portion;
an engaging portion protruding from the connecting portion so as to extend from the screw portion side to the support shaft portion side and capable of coming into contact with the screw support portion in a state in which the support shaft portion is supported by the screw support portion; with
The end portion of the engaging portion on the threaded portion side is formed only of a skin layer and does not include a foam layer,
The optical axis adjusting screw according to claim 1. The foaming rate in the foam layer is 1 to 10%,
The optical axis adjusting screw according to claim 1 or 2. A vehicle lamp comprising the optical axis adjusting screw according to any one of claims 1 to 3.

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